


Son of the Sea

by bonniepride



Series: Big Hero Mer [4]
Category: Big Hero 6 (2014)
Genre: Adoption, Daniel Hamada, M/M, Mer AU, Merman! Tadashi, Parents, merbaby, mermaid au
Language: English
Status: Completed
Published: 2016-12-12
Updated: 2016-12-12
Packaged: 2018-09-08 00:43:26
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,917
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8823145
Author URL: https://archiveofourown.org/users/bonniepride/pseuds/bonniepride
Summary: Tadashi and Fred are newly married and finally returning home after their amazing honeymoon. But just as they're getting ready to settle down to married life, a mysterious call from Professor Callaghan about an orphaned merbaby changes everything. (Rating for implied honeymoon fluff)





	

Tadashi awoke to feel the warm sun shining down on his face through the blinds. He stretches slowly as his sleepy brain wakes up, taking it’s own sweet time, but he didn’t mind. While it was, he could just lie here in a blissful half-awake state and watch his husband’s chest gently rising and falling, an adorable smile on his beautiful face.

Yes, husband. It was still so hard to believe that they were actually _married_ now. Tadashi hadn’t yet convinced himself that this wasn’t all some wonderful dream and he was going to wake up in his pool, his little brother telling him that this whole amazing fairytale of a past four years had been just that--a fairytale. From the true love’s kiss that had freed him from the family curse (magical, genetic, or otherwise) of being born with a tail instead of legs to the beautiful seaside wedding they’d had only two weeks ago, the whole thing seemed like something straight out of a Disney movie.

Tadashi had been dreaming of finding his prince charming since he’d been a little guppy, left alone to fend for himself in the pool inside his family’s ancestral mansion by parents who were too disgusted by their “freak” of a son to properly care for him. His strong belief that finding his “true love” might save him from a horrible future of being bound by those four concrete walls for the rest of his life had only strengthened when his aunt had started reading him and his human little brother, Hiro, to sleep every night with stories from an old book of fairytales after their parents died in a car accident.

Of course, his plan had its flaws--he was never allowed to see anyone outside of his two remaining family members and his tutor, so where was he supposed to find his prince unless he somehow procured one out of thin air? By the age of eighteen, he was starting to feel a bit discouraged--dreams could only last so long without any evidence that they were going to come true.

Just as he was about to give up hope on ever finding true love, let alone a friend outside of his little brother (not that he didn’t love him dearly, but fourteen years of having only one person as your companion was pushing it), Fred had come stumbling into his life--almost quite literally. The mer would never forget the day that he’d come up to the surface to investigate the unusual sounds of disturbance in his private sanctum, only to find that the new houseboy had broken into the room, trying to figure out what kind of secret the mysterious family down the street was keeping. Tadashi could almost guarantee that the poor fanboy hadn’t been expecting to find a real live mer in the house, and even less for said mer to try to seduce him in hopes of getting a kiss that might free him from the curse. The elder Hamada had managed to get the kiss, but it hadn’t done anything--at least not at first. After that rather awkward start to the relationship, Fred had admitted to mutual attraction and agreed to start dating him to see what might happen (Tadashi's family hadn’t approved of the match at first, but eventually they’d come around to it when the fanboy had proved to be trustworthy, never so much as even hinting at giving away the mer’s secret and putting him in danger.)

Over the summer, the two had developed a deeper relationship, friendship and then love blooming between them, culminating in a real true love’s kiss after Fred had managed to fulfil one of the mer’s greatest life dreams--taking him on a tour of SFIT, his dream university where he’d always wanted to learn robotics under his hero, Professor Robert Callaghan. After the kiss, with practice, Tadashi had found that he could switch between mer and human at will--it had taken a lot of training to learn control, but in the end he had managed it well enough to be able to pass himself off as perfectly human when he wanted to.

Not to say that a few people didn’t find out his secret before he’d managed to get a lock on it. Three other teens they’d met on the SFIT tour (nicknamed Wasabi, Honey Lemon, and GoGo by Fred) had discovered his secret when they’d walked in on him stretching his tail (he’d spent most of the day keeping it hidden under blankets and a custom made moisturizer that kept him from drying out while his boyfriend and brother had pushed him in a wheelchair around campus, but a tail could only take so much of that before it started seriously cramping!) Then there had been the time at the Expo (an event where SFIT hopefuls presented research or inventions they’d been working on) when Tadashi had jumped into a pool to save a girl who had fallen in, his body automatically transitioning into mer form the second he’d hit the water. It had seemed like he was going to be taken away to be locked up and experimented on, but Hiro had managed, through some very fast talking and maybe a bit of mer persuasion, to convince all of the judges watching that the tail was just another one of the brothers’ inventions.

What they hadn’t known at the time was that Professor Callaghan, who had been the head judge, hadn’t believed their story but had kept their secret all the same because his late wife had been a mer as well. They hadn’t found that out until two summers later, when they’d run into him while visiting Fred’s beach house and Callaghan had rescued Hiro (who by then had gained his tail on his sixteenth mer coming-of-age birthday thanks to a platonic brotherly true love’s kiss on the forehead from Tadashi) from a fisherman who had managed to catch him in a net and wanted to use him as a sideshow attraction. So, despite how many of those encounters could have gone horribly wrong, by some miracle they’d all resulted in helping Tadashi find amazing friends and powerful allies who were all determined to help him protect his secret. And those same people had all been there when Fred had finally proposed to him on the night of graduation in the cafe, surrounded by their loved ones, and a year later when the two had finally tied the knot.

So here Tadashi was. Waking up on the last day of their extended honeymoon. With his and Hiro’s company, Hamada Bros’ Inc, just starting up, he hadn’t been sure that they could afford to take a break like this, but his younger brother had insisted, saying that he just expected him to return the favor if (or, more appropriately at this point, when) he and his boyfriend, Ezra, ever got married. The trip itself had been amazing--travelling all of Europe, both to the most romantic spots, like Paris, and to the nerdiest spots, like the places that had been used to film the Harry Potter movies. And getting to be alone with his new husband, waking up next to him every morning and falling asleep after making sweet love every night, had been like something straight out of a fairytale. Part of Tadashi was sad to see it coming to an end, but the other part of him was ready to get home to see all their family and friends again and start their married life in the small apartment the two had rented--despite the fact that both their families had more than enough room for them to comfortably live with them if they wanted to, the young couple wanted a chance to enjoy living on their own, just the two of them. With Fred staying at home to work on his novel while Tadashi worked with Hiro in the small office they were currently renting, it sounded ridiculously domestic and homey, and neither of them could wait for it to start.

“Good morning.” Tadashi was pulled out of his thoughts by the sound of his husband’s voice, and he grins when he sees the beautiful cerulean eyes he loved so much looking at him, pure love shining in them.

“‘Morning,” Tadashi breathes, leaning in to kiss the other man, who more than happily returns it, wrapping his arms around his husband’s bare torso and gently pressing against him.

“You ready for some breakfast?” Fred asks when they finally break for air.

“Mm,” Tadashi agrees, nodding and smiling even as he lets his hands wander freely over his spouse’s naked body.

“Or, y’know, if you wanted to get another round in before breakfast…” Fred chuckles, gently taking his hands in his own.

“Maybe…” Tadashi answers playfully.

“C’mon, I know you better than that!” Fred leans in and gently pushes his husband down onto the mattress. “You totally want to!”

“Okay, yes I do!” Tadashi chuckles, pecking his lips as the fanboy straddles him.

“You ready to make one more honeymoon memory?” Fred playfully purrs in his ear.

“Definitely!” Tadashi agrees, grinning up at him.

 

Eventually the two did get to breakfast (albeit a bit late), being ridiculously cutesy about it--feeding each other bites of belgian waffles and of course purposefully getting whipped cream on each other’s noses--before heading back up to the room they’d been staying in at the little bed and breakfast to finish packing. A few hours later, they were heading to the airport and boarding their flight back to home. It was a long flight, but they easily passed it marathoning their favorite shows and looking through the pictures from their honeymoon.  

Given they had left out at noon from London, by the time they finally touched down in San Fransokyo they were on 2 am England time even though it was only 6 pm in California. Fortunately they had thought ahead and taken a nice long nap on the plane so they weren’t completely out of it when they touched down at the airport. Still, both of them were more than happy when they see Aunt Cass waiting for them outside the doors for “Arrivals” to drive them back to the mansion for a home cooked meal before they picked up their car and headed back to their own apartment to actually get a good night’s sleep. (It was going to take them a few days to get back on the California time table again, but hopefully staying up a bit so that they’d actually go to bed at a normal time tonight would help with that.) The elder Hamada wasn’t completely surprised when his younger brother turned out to be waiting for him in the backseat, eagerly pouncing on him a giant bear hug as if he was a little kid instead of being nineteen years old before dragging him into the cab, begging for all the details of the trip. Tadashi was slightly sleep deprived, but he was honestly really happy to see his little brother too and he answered all of his questions as best he could, Fred chiming in to help him out.

When they reach the mansion, Tadashi was extremely relieved that Aunt Cass had kept her promise of keeping it to just a simple family dinner and hadn’t tried to “surprise” them by inviting all of their friends over too. As much as he loved them all and wanted to see them soon, he just didn’t have the energy for it right now. Still, he couldn’t resist checking on them and so he asks, “Did everyone get home okay?”

“Oh, definitely!” Aunt Cass reassures him before admitting, “Well… I honestly don’t know about your professor friend. I don’t think he’s back yet, but you said that he was spending some time down by the beach since he’s on vacation from the university for the summer, right?”

“Right,” Tadashi agrees. “He’s doing some research.” Research on mers, that was--trying to figure out why it seemed like there were so many occurences of mers in such a concentrated area (Callaghan’s wife and the Hamada family, to name two such cases.) Callaghan’s wife had been an orphan so she hadn’t had much information for him even when she had been alive, but now the professor was trying to find out if there was actually a mer community well hidden in the general area or if there were just a few surviving remnants who were so desperate for companionship that they were willing to risk talking to humans just to defeat the crippling loneliness that they felt. It wasn’t a very pleasant mental image if it was the latter case, but he felt like he needed to know and, if at all possible, see if there was something he could do to help if that was the case.

Suddenly, as if reading their minds, Tadashi’s phone starts ringing and he pulls it out of his pocket, feeling a combination of surprised and pleased to see his professor calling. “Be back in a second!” he promised the others, gently pecking his husband on the cheek before heading into the living room to answer it.

“Hello, _sensei_ ,” he greets the older man, holding the phone to his ear and smiling. “How are you?”

“Tadashi, I’m glad I caught you! I was afraid that you weren’t back yet!” Callaghan answers, not wasting any time with formalities. “You are home, right?”

“Y-Yeah, we just got back, actually--we’re at Aunt Cass’, she picked us up from the airport,” Tadashi answers, his brow furrowing in concern at his professor’s tone--not panicked, exactly, but a very controlled amount of urgency that was his equivalent.

“You’re at your aunt’s? Good, stay there!”

“W-Why--? _Sensei_ , what’s going on?”  

“I think it would be better if I just showed you. I’m on my way back, I should be there in about two hours--can you stay at your aunt’s until then?”

“Y-Yeah, I guess so…” Tadashi was feeling completely confused and honestly a little bit worried by now, but he was doing his best not to let his agitation out into his voice. He still trusted his mentor without questioning after all these years, even if he could be as cryptic as Dumbledor when he wanted to.

“Good. Just one more question for you.”

“Yeah?”

“Besides salt water, what else do you need to keep a mer alive when transporting them?”

“Uh…” Tadashi’s mind completely blanks out. Wait, had he just said--?

“Damn, I’m about to go into a dead zone, you’re cutting out. I’ll just trust this is enough and I’ll see you when I get there.”

Even after his professor had hung up, Tadashi just stayed there for a full minute, frozen, his brain not processing what had just happened.

“Dashi?” He jolts slightly when he feels his husband’s hand on his shoulder. “What is it? What’s wrong?”

“I--I don’t know,” Tadashi admits numbly, finally turning to him. “I think… I think Professor Callaghan is bringing a mer here!”

The next couple of hours were spent in a quiet sort of panic. As much as they all wanted to try their best to prepare for their potential visitor, with so few details there wasn’t much they could do, so Aunt Cass insisted that everyone finished dinner before beginning the awkward stage of just sitting around and pacing, none of them sure what to say. Somehow now didn’t seem the time to share pictures and stories from the honeymoon, and while Aunt Cass did her best to create small talk to pass the time, only Fred actually answered her queries out of politeness. Tadashi found himself constantly watching out the front window, his heart rising and then falling at every pair of headlights that passed the gates. He wasn’t sure what he was feeling. Part of him was excited--another mer, coming here! This would be his first time meeting an actual mer outside of his family, so this was a pretty big deal! On the other hand, he had no idea what to expect of a wild mer. What would they think of a mer who lived among, was married to a, and could even turn human? Would they be accepting or consider him some sort of freak? As much as he knew it really didn’t matter what a stranger who didn’t even know him thought, the idea still weighed on him. And there was something else--why was Callaghan bringing a mer _here_? Wouldn’t it be better off living in the ocean? Maybe it was a mer that had been captured by humans and been living in captivity and so didn’t know how to survive in the wild? That was always a possibility. Or… Oh gosh, what if they were injured? Sometimes when mers got too close to human areas, they got into accidents with boats or fishing equipment--Callaghan had lost his own wife to a drunk boater. Given how little his professor was saying about the situation, that could be it--maybe the poor mer was so badly injured that he didn’t want them to know just how bad off they were until they got there!

All these possibilities and more swirled round and round in his head until he was sure that he was going to go crazy at the uncertainty. Just as he was at the point of screaming, suddenly a pair of headlights flash at the gate before heading up the front drive.

 _Finally!_ Tadashi hurries to unlock the door, and the others quickly join him, the entire family rushing out to meet the professor as his car comes to a stop.

“ _Sensei_!” Tadashi calls, hurrying over to the older man as he opens the door to the driver’s side and he climbs. “H-How bad is it? Are they hurt badly?”

“No, thank goodness,” Callaghan answers, not even noting his lack of a proper greeting. “The mother… Wasn’t so fortunate, I’m afraid to say.”

“T-The mother?” Tadashi repeats, slightly caught off guard by his answer.

“I think you’d better come and see.” Callaghan waves for him to follow him, and the other man obligingly does so, his curiosity now extremely piqued.

“He’s in here,” the professor says, opening the passenger side door where a large plastic tub was strapped to the seat using bungee cords, ropes, and apparently anything else that he’d been able to find to safely strap it in.

An odd mixture of trepidation and excitement in his chest, Tadashi leans over to see what’s inside it, only to let out a tiny gasp when he catches his first glimpse of its current inhabitant.

“Oh…” he breathes. There, sleeping peacefully in the water, was the tiniest, most perfect merbaby he’d ever seen. Technically, it was the only merbaby he’d ever seen, but somehow in his mind he’d already decided that it was the cutest one in the whole world. Without even thinking about it, he automatically reaches into the tub, scooping the tiny form up into his arms and cradling it close to his chest.

“Hi…” he whispers softly, using one hand to stroke the soft brown hair on it’s head, unable to look away from its tiny, perfect features, from the little bitty fingernails to the blue scales glistening on its tail.

“Dashi? What is it, what did you--Oh my gosh!” Tadashi doesn’t even look up when he hears his husband’s voice, just turning so that the other man could see the baby better.

“Isn’t he perfect?” he says softly, feeling like his heart had already been claimed by the tiny life he was holding in his arms.

“He’s… Certainly cute…” Fred answers slowly, if a bit cautiously. “But what is he doing here?”

“Like I started to tell Tadashi,” Callaghan says, finally speaking again, “I found the mother in the harbor. Apparently she’d come too close to the shore--possibly in search of food since there’s been a problem with overfishing in the area recently, possibly for some other reason we’ll never know. She must have gotten into a collision with a boat--by the time I spotted her, it was… too late.” The older man’s whole body seems to sag as he recounts the story. “I tried to keep her calm, but she kept trying to give me her bag. Eventually I took it, and that’s where I found this little one. She must have known that she wasn’t going to make it and wanted to make sure that someone took care of her son.”  
“So you brought him here?” Fred asks in disbelief.

“I couldn’t leave him there!” Callaghan answers. “He wouldn’t have survived a day on his own in the sea!”

“But weren’t there… Y’know, other mers living somewhere around there?” Fred presses. “Weren’t they the ones who you were looking for all this time? Maybe he has relatives who are worried about him!”

“Unfortunately, mers seem to have greater powers of staying hidden when they don’t want to be found than I bargained for,” Callaghan answers dryly.

“That’s pretty convenient…” Fred quietly mumbles.

“Fred, you’re not being very sensitive about this!” Tadashi snaps. “Someone just _died_ ! This poor baby is an _orphan_! At least show a little respect!”

“I…” Fred flushes slightly before mumbling, “C-Can we talk alone, please?”

“Why?” Tadashi asks, not wanting to let go of the baby in his arms.

“Just come with  me. Please…” Fred answers, looking pleadingly at him.

“...Fine,” Tadashi finally relents. He carefully settles the tiny mer back into it’s makeshift crib, but not before gently kissing its forehead and whispering, “I’ll be right back, okay?”

“I know what you’re going to say,” Fred says when the two are finally a little ways away from the other.

“That you’re acting like an insensitive jerk?” Tadashi quietly huffs, crossing his arms over his chest.

“Not that! I--I can see it on your face already… You want to keep him, don’t you?” Fred answers, not quite meeting his husband’s eyes.

“Maybe....” Tadashi says noncommittally. “So what if I do?”

“Tadashi, he’s not a puppy! There’s a lot more responsibility that goes with raising a kid, _especially_ a mer one!” Fred fires back. “And, in case you forgot, we are married! Don’t you think you should consult me before deciding that you want to adopt a kid the minute we get back from our honeymoon?”

“Technically we’ve been back for two hours, not a minute…” Tadashi mumbles, making a poor attempt at humor even as he fights the tears suddenly pricking at his eyes.

“Dashi…” Fred lets out a low sigh, absently pushing the hair back off of his forehead. “I just… Are you even thinking about what all this would entail for us? We’re not going to get any time alone as newlyweds--we’d be going straight into being parents, something neither of have even really prepared for!”

“W-We’ve talked about wanting to have kids before!” Tadashi protests.

“Yeah, in a few years when we’ve settled down and you’ve got your company going with Hiro!”  
“So it’s a little early! We can make this work!”

“Tadashi… Are you really to make all of the sacrifices this is going to take? I mean, we’d probably have to move back in with your aunt so the poor little guy would have an actual place to live.”

“Not until he gets older--!”

“But it would happen eventually. And with you being at work with your company, I’d be the one having to look after him during the day. I don’t know the first thing about taking care of babies!”

“A-Aunt Cass could help--!”

“She has her cafe to look after.”

“Well--I-I could work from home!”

“Not all the time, you couldn’t.”

“I--I know…” Tadashi’s shoulders slump in defeat. “I’m sorry… I know how selfish I’m probably being, I just…” He feels tears starting to actually slip out and course down his cheeks. “I-I saw him, and then I held him in my arms and I just… I could feel it. H-He belongs with us… I--I can’t even imagine giving him away to someone else…”

“Oh, Dashi…” Tadashi feels his husband’s arms wrapping around him, and he tightly clings to him as he cries.

“You really want him, don’t you?” Fred says softly.

“I-I do,” Tadashi answers, his voice muffled by the other man’s shirt. “I want him so much… I-I didn’t even know it was possible to fall in love with someone that fast…”

“You’re just an amazing person with a really, really big heart,” Fred answers with a soft smile, gently stroking his husband’s hair. “And... How can I say ‘no’ to my husband when this is the first thing he’s ever actually asked me for?”

“W-Wait…” Tadashi stammers, looking up at him in surprise and trying not to get too hopeful. “A-Are you saying…?”

“Okay,” Fred answers, gently kissing his forehead. “It’s not going to be easy, but we can make this work. It’s not like the little guy really has anywhere else to go, right? And he is kind of cute…”

“Y-You’re serious?” Tadashi gasps. “W-We can really keep him?”

“Absolutely,” Fred answers with a smile of his own.

“T-Thank you!” Tadashi wraps his arms tighter around him. “You are the best husband in the whole world!”

“You’re going to be saying a lot of that after this,” Fred answers playfully. “Now c’mon--let’s go see our son, huh?”

“Yeah!” Tadashi agrees, beaming up at him. Son--they actually had a son!

They return to the car to find Aunt Cass fussing over the baby, who was awake now if the fact that there were loud cries coming from the car was any sign. Instantly her nephew’s gait quickens, and Fred’s matches it, Tadashi not even noticing how concerned he was looking for the baby’s safety in his own hurry to get to the car.

“Poor little thing won’t stop crying,” Aunt Cass sighs. “I’ve tried everything I can think of that used to work with you two…”

“I might have an idea,” Tadashi answers. He quickly undoes the restraints on the tub before moving it gently to the ground and then climbs into the passenger side seat. From there, he goes into mer form, his legs morphing into a long silver tail before reaching down into the tub and carefully pulling the little merbaby out of the water and settling it on his lap. Almost instantly, the tiny mer stops crying, looking up at him with wide-eyed curiosity.

“There--that probably feels more like what you’re used to, huh?” Tadashi says softly, gently bouncing the baby on his lap before cradling it against his chest. The tiny child lets out a musical gurgle before gently nuzzling against him, seeming quite content in his arms.

“C-Can I try holding him?”

Tadashi looks up in surprise to see Fred standing next to him, a hesitant if somewhat excited note in his voice.

“Sure,” Tadashi answers, beaming up at his husband and carefully transferring the baby to his arms.

“Hey there…” Fred smiles down at the tiny mer in his arms a slight sparkle coming into his eyes. “So, apparently I’m going to be your new daddy. How do you feel about that?”

If the baby had any complaints, he certainly didn’t voice them, instead beaming up at the fanboy and wrapping his tiny fist around the man’s finger.

“O-Oh my gosh!” Fred gasps, a happy glow coming over his features. “D-Did you see that?”

“I did!” Tadashi answers, grinning. “He likes you!”

“You think?”

“Definitely!”

“Well, I’m sure he loves his papa too!”

“Oh, so I’m his ‘papa’ and you’re his ‘daddy’? When did we have this discussion?” Tadashi asks playfully.

“You chose to adopt him, so I get to choose names!”

“Okay, fair enough!” Tadashi chuckles.

“So, you are going to take him, then?” Callaghan asks, coming over to join them. “I didn’t want to force him on you, and I would have taken himself in myself if he didn’t have anywhere to go. But I thought he’d be better off having at least one mer parent, if at all possible.”

“Yeah,” Fred agrees, grinning over at Tadashi--it was obviously that he’d already lost his heart to the little boy in his arms too. “We are definitely keeping him.”

“Oh my gosh, my first grandbaby!” Aunt Cass cries excitedly.

“Wait, so I’m an uncle now?” Hiro says, seeming a bit confused by how fast everything was happening but definitely not averse to adopting the new title.

“I guess so!” Tadashi chuckles.

“Now all we have to do is figure out what to call him,” Fred adds, gently rocking their tiny son in his arms.

“Actually, I think he already has a name,” Callaghan answers, reaching into the water and pulling out a soggy piece of blue fabric that Tadashi hadn’t even noticed before out of the tub. The older man wrings it out before handing it to him, gesturing to the bottom corner where, in tiny glittering stitches, letters spelled out the name “Daniel”.

“Daniel, huh?” Tadashi says softly, smiling as he switches back into human form so that he can stand next to his husband and their new son. “Well, welcome to the family, Daniel Lee-Hamada. We’re all super happy to have you here.”

“Yeah,” Fred agrees, beaming over at the other man. “All of us.”


End file.
